Marionia distincta Bergh, 1905

Description

The living animal is about 36 mm long and 7 mm wide. Body colour reddish-grey, with black transverse lines on the dorsal margin and blackish leaf-like portions on the dorsal arm-like papillae. After preservation the body becomes uniformly yellowish, the transverse lines on the dorsal margin disappear, and the leaf-like portions become greenish-black.

The frontal veil is not strongly developed, with its margin slightly notched in the middle and bearing 11 nearly cylindrical appendages, finely tuberculate especially on the underside; the outermost appendage has a longitudinal groove. The smooth dorsum is more than twice as broad as the foot and bears on each side 9 arm-like papillae, each rather deeply forked with a leaf-like portion on each branch. The anterior six arms alternate in size; the posterior three are smaller and decrease in size backwards. The second and especially the fourth arm are the largest. The anal papilla stands at the outer base of the fourth arm and the genital papilla farther forward, between the second and third arms. The narrow foot is rounded in front, and the tail is short.

Distribution

Type locality: anchorage east of Sailus Besar, Paternoster Islands, Indonesia. Originally based on a single specimen.

Etymology

The specific epithet distincta is the feminine of Latin distinctus ("distinguished, separated, distinct"), reflecting that the species was established as clearly separable from the congeners M. arborescens and M. chloanthes.

Remarks

Known from very limited type material from the western Pacific.

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References

• Marionia distincta Bgh. n. sp., Bergh R. (1905). Die Opisthobranchiata der Siboga-expedition. https://doi.org/10.5962/bhl.title.11223
• Marionia distincta, Terrence Gosliner, Ángel Valdés and David Behrens. (2018). Nudibranch and Sea Slug Identification Indo-Pacific 2nd Edition. New World Pubns Inc.